Basin 17 - Lake Memphremagog, Coaticook and Tomifobia Rivers Basin Planning

Lake Memphremagog - looking north into Quebec

Basin 17 includes the Vermont portions of the St. Francis River Watershed encompassing a total of 589 square miles between the Lake Memphremagog drainage and the Tomifobia and Coaticook River watersheds. The Vermont portion of this basin includes the Black, Barton and Clyde Rivers and many lakes and ponds, including Great and Little Hosmer Lakes, Lake Parker, Shadow Lake, Crystal Lake, Lake Willoughby, lake Salem, Island Pond, Great and Little Averill Ponds, Norton Pond, Holland Pond and Seymour Lake.  

Phosphorus Total Maximum Daily Load (TMDL) and 2017 Tactical Basin Plan

Lake Memphremagog is shared with the province of Quebec, with a majority of the lake in Quebec, but a majority of the watershed in Vermont. Phosphorus levels in Lake Memphremagog are above the Vermont State Water Quality Standards. Excess phosphorus that runs off the land into the lake causes occasional cyanobacteria blooms and nuisance plant and algae growth, which limit the recreational use of the lake. The Total Maximum Daily Load or TMDL for Lake Memphremagog, developed using lake and watershed models and approved by the Environmental Protection Agency (EPA) in September 2017, calls for a 29% reduction in phosphorus inputs. 

The Lake Memphremagog, Coaticook and Tomifobia Tactical Basin Plan was approved in November of 2017. It identifies specific actions to reduce phosphorus and sediment pollution from farmland, roads, developed lands, wastewater treatment facilities, forest lands and wetlands, along with addressing water level fluctuations and aquatic invasive species spread over the next five years. It also outlines additional concerns in the basin, including two streams, Roaring Branch and an unnamed tributary to Stearns Brook that are impaired from nutrient runoff from farms; 13 additional lakes in the watershed with either elevated levels of phosphorus or increasing phosphorus trends; water level fluctuations on lakes and streams in the Coaticook watershed; and the spread of aquatic invasive species. The Vermont Department of Environmental Conservation adopted a new wastewater treatment facility wasteload allocation for facilities in the Lake Memphremagog watershed.

Learn about projects in your area, and view more than 350 specific actions for the Lake Memphremagog, Tomifobia and Coaticook Basin through the Watershed Projects Database. Select "Basin 17-Lake Memphremagog" and click on the “Search” button. 

Visit the Restoring Lake Memphremagog webpage to learn more about the Lake Memphremagog TMDL and work of the Quebec Vermont Steering Committee on Lake Memphremagog.

Contact Ben Copans at 802-490-6413 with any questions about the TMDL or tactical basin plan.


2012 Tactical Basin Plan

In 2012, the Basin 17 water quality management plan was approved with goals reduce nutrient enrichment and exotic invasive species and to improve aquatic habitat conditions.  In total 79 specific actions were identified in the plan to achieve these goals of which more than three quarters have been initiated or completed as of 2016 as can be seen in the report card at this link.  Some highlights include:

  • Illicit discharge detection and elimination study completed for all basin communities.
  • Stormwater master planning completed for Brighton, in progress across in other areas of the watershed.
  • Over 4 acres of buffer plantings completed across the watershed each year through the NorthWoods Stewardship Centers Trees for Streams program and 6 lakeshore buffer plantings.
  •  Rain garden instillation and rain barrel sales by the Memphremagog Watershed Association and numerous outreach events each summer.

02/01/2012 Final Basin 17 Water Quality Management Plan and Appendix

Additional Resources